TY  - JOUR
AU  - Gudlaugur Thorbergsson
TI  - Non-hyperbolic closed geodesics.
JO  - Mathematica Scandinavica
PY  - 1979
SP  - 135
EP  - 148
VL  - 44
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MS2_1979__44_166637/
ID  - MS2_1979__44_166637
ER  -